DE2818093A1 - METHOD FOR PRODUCING A SURFACE COATING - Google Patents

Description

Patent Attorney - April 5, 1978

DR.RICHARD KMEISSL 9 P.

Widormayerstr 45 4th Q \

Widor.mayerstr. 45

D-GOOO MUNICH Tel. 0 39 / '29 5125

Cap 24 447 ICI Case No. PV. 29504A / 29505A / 29685

IMPERIAL CHE] VIICAL INDUSTRIES LIMITED London / Great Britain

Process for the production of a surface coating

809845/0797

description

The invention relates to a method for producing protective and decorative coatings on surfaces, in particular on the surfaces of automobile bodies.

It is known, coating compositions, especially those for use in the automotive industry, to be formulated on the basis of polyester resins. Such resins can be obtained from the air-drying Alks'dtype, v / o with them autoxidizable groups that are derived from natural drying oils, in which case the hardening of the resin to form a film is based on the action of atmospheric oxygen. Alternatively they can not contain any autoxidizable groups, • in which case the hardening is based on the reaction of the remaining ones present Hydroxyl or carboxyl groups with a crosslinking agent such as 3. an amino resin, based on, following the application a curing step is added to the coating composition on the substrate. Often a combination of both is also used Hardening mechanisms used. These polyester-based compositions however, give rise to certain difficulties, in particular when applied by spray, as is normally done on car bodies. In those cases where such a composition is applied as a top paint on the car body, the TSunscii can be used to achieve good flow of the Coating after application to obtain maximum gloss, incorporation of film-forming components with very low Require molecular weight. However, these tend to make the composition excessively flowable during spraying do what leads to the appearance of snot noses. In other cases where a polyester based composition is considered pigmented Undercoating is used, especially if it contains a metal flake pigment, followed by an unpigmented pigment Topcoat by a conventional wet-on-wet process is applied, a major requirement is that the application of the top coat does not affect the bottom coat.

809845/0797

gives way and thus the orientation of the metal flakes (through which a "metallic effect" is achieved) destroyed. To this requirement To meet, a film-forming material with a high molecular weight is necessary, but it is often difficult to find suitable polyesters Select formulations which enable the achievement of high molecular weights without problems of high viscosity or the risk of gelation occurring during manufacture.

It has now been found that an improvement in the spray properties a coating composition based on a polyester resin can thereby be achieved. That one in the composition a proportion of polymer microparticles of a certain type incorporated.

The invention therefore relates to a method for production a surface coating on a substrate, which is characterized in that one is sprayed onto a substrate Applies coating composition containing the following:

(A) a film-forming polyester resin as defined below;

(3) a volatile organic liquid diluent, in which the polyester resin (A) is dissolved;

(C) Polyrasr microparticles as defined below in an amount of at least 3% of the total weight of the resin (A) and the microparticles which are insoluble in the solution of the polyester resin in the diluent (B) and are stably dispersed therein,

and that the volatile diluent (B) is then evaporated off and a polymer film is formed on the substrate surface.

By the term "film-forming polyester resin" is used herein a resin which is known in the art to be used for surfaces

809845/0797

coating compositions can be used. It deals are essentially the products of the condensation of polyhydric alcohols with polycarboxylic acids. Under this expression also include "alkyd resins" which are obtained from such starting materials with the addition of constituents which contain fatty acid residues supply made of natural drying oils or semi-drying Oils or even oils without air drying properties derive. This expression is also intended to include polyester resins that do not contain any natural oil residues. All of these resins normally contain a proportion of free hydroxyl and / or carboxyl groups which are suitable for reaction with suitable crosslinking agents available, which are discussed in more detail below. If a crosslinking agent is used it will considered part of the film-forming ingredient (A) for the purposes of the above definition of the invention.

Suitable polyhydric alcohols for the production of polyester resins are ethylene glycol, propylene glycol, butylene glycol, 1,6-eexylene glycol, ileopentyl glycol, diethylene glycol, triethylene glycol, Tetraethylene glycol, glycerine, trimethylolpropane, trimethylolethane, Pentaerythritol, dipentaerythritol, tripentaerythritol, hexanetriol, Oligomers of styrene and allyl alcohol (such as those sold under the designation RJ 100 by Monsanto Chemical Company are sold) and the condensation products of trimethylolpropane with ethylene oxide or propylene oxide (such as the products commercially known as "Niax" triols). Suitable polycarboxylic acids are succinic acid (or its anhydride), adipic acid, Azelaic acid, sebacic acid, shark acid (or its anhydride), fumaric acid, muconic acid, itaconic acid, phthalic acid (or its anhydride), isophthalic acid, terephthalic acid, trimellitic acid (or its anhydride) and pyromethic acid (or its anhydride). If it is desired to prepare an air drying alkyd resin, then suitable useful fatty acids are from drying oils those that differ from flaxseed oil, soybean oil, tall oil, dehydrated Derive castor oil, fish oil or tung oil. Other oleic fatty acids of the semi-drying or non-drying types which

809845/0797

3 2B18093

are those derived from safflower oil, sunflower oil or cottonseed oil. It is normally preferred that the oil length of such alkyd resins not exceed 50? O. Conofunctional saturated carboxylic acids can also be incorporated to impart some plasticity to the polyester. Such acids can be, for example, saturated aliphatic C 1-4 acids, benzoic acid, p-tert-butylbenzoic acid and abietic acid. Indeed, these may be the only fatty acids in which the polyester resin is cured by subsequent reaction of residual hydroxyl or carboxyl groups with a crosslinking agent. In addition, monofunctional hydroxy compounds can also be incorporated in order to control the chain length of the polyester or to impart certain desired compatibility properties to the polyester. Suitable Konohydroxyverbindungen are benzyl alcohol, cyclohexyl alcohol, saturated or unsaturated fatty alcohols and condensation products of ethylene oxide or propylene oxide with monofunctional alcohols (eg, methoxy-polyethylene glycol obtained by reaction of ethylene oxide with methanol).

Suitable film-forming polyester resins are also "modified" alkyd resins, such as styrenated or methacrylated alkyds, urethane alkyds and epoxy alkyds.

The volatile organic liquid component (B) of the composition can be any liquid or any mixture of liquids that are commonly used as polymer solvents in coating compositions, such as aromatic hydrocarbons, for example toluene and xylene and petroleum fractions with various boiling point ranges that have a considerable aromatic content , Esters, for example butyl acetate, ethylene glycol diacetate and 2-ethoxyethyl acetate, ketones ,. for example acetone and methyl isobutyl ketone, and alcohols such as butyl alcohol. The liquid or liquid mixture selected in each case as diluent (B) depends on the nature of the film-forming polymer (A) , according to the principle

8098AS / 0797

principles that are generally known in coating technology, so that the polymer is soluble in the diluent.

The polymer microparticles (C) contained in the composition used in the present invention are polymer particles of colloidal dimensions with a diameter of 0.01 to 10 µm, which are insoluble in and the solution of the polyester resin (A) in the diluent (B) are stably dispersed (in the sense that they do not suffer flocculation or aggregation while dispersed in these iledium). The insolubility of the microparticles can be achieved by suitable selection of the composition of the polymer of the microparticles, ie that the polymer should be one which is inherently insoluble in this combination. However, this insolubility is preferably achieved by introducing a sufficient degree of crosslinking into the polymer that, if not crosslinked, would actually be soluble in the solution of the polyester resin (A) in the diluent (B). If the insolubility of the microparticles is achieved by crosslinking, then it is preferred that the degree of crosslinking be no greater than that required to render the polymer insoluble. The insolubility of the microparticles in the solution of the polyester resin (A) in the diluent (B) can be determined by the following test. The microparticles (1 part by weight) are shaken with the diluent (B) (100 parts by weight) for 30 minutes. The suspension is then centrifuged at 17,000 rpm for 30 minutes. The supernatant liquid is decanted off and the residual polymer then dried for 30 min at 15O ⁰ C, after which its weight mit.dem weight of the original microparticles is compared. This test can be difficult to perform when the specific gravity of the diluent is near or above that of the microparticles, however, such diluents (such as chlorinated solvents) are normally "not used in the compositions under consideration. If the result of this test indicates that the microparticles have a useful insolubility in the diluent (B) alone, then reasonable

809845/0797

it can be assumed that the particles are at least equally insoluble if the polyester resin (A) is also in solution in the diluent is present. There are practical "difficulties" in carrying it out of the test in a solution of the polyester resin (A) in the diluent (B).

The polymer microparticles can be of various types. she can for example consist of an addition polymer that is in front of. one or more ethylenically unsaturated monomers derives. In particular, they can be made from a polymer or mixed polymer of one or more alkyl esters of acrylic acid or methacrylic acid and optionally other monomers, such as vinyl acetate, Acrylonitrile, styrene, acrylic acid or methacrylic acid exist. Suitable acrylic and methacrylic esters are methyl methacrylate, Ethyl methacrylate, propyl methacrylate, butyl methacrylate, ethyl acrylate, Butyl acrylate and 2-ethylhoxyl acrylate. If it is desired In order for such a polymer to be crosslinked, this can be accomplished in one of two general ways: first, by incorporation a minor amount of a monomer which is polyfunctional with respect to the polymerization reaction, such as ethylene glycol dimethacrylate or divinylbenzene, into the monomers of which the polymer is derived; or, secondly, by the incorporation of smaller! -! er., two larger monomers, the pairs of chemical Carry groups which can be caused to react with one another during or after the polymerization reaction, such as epoxy and carboxyl (e.g. glycidyl methacrylate and methacrylic acid), anhydride and hydroxyl or isocyanate and hydroxyl, in such monomers. Alternatively, the microparticles can be composed of an analysis polymer, for example of a polyester composed of one of the polyhydric alcohols described above and one of the polycarboxylic acids described above will be produced. Such polymers can also be crosslinked if desired by incorporating materials with a functionality of more than 2 in the initial composition, although in this case because of the characteristic broad molecular weight distribution of the condensation polymer

809845/0797

- -κι -

formation of molecules it can be difficult to ensure that all molecules are indeed networked.

The chemical compositions and the degree of crosslinking of the Polymers of the microparticles can be such that they have a Tg (Glass-rubber general temperature) below room temperature, in which case the microparticles are rubbery in nature ". Alternatively, they can be such that the Tg is above room temperature i.e. that the particles are hard and glassy.

As previously stated, it is necessary that the polymer microparticles are stably dispersed in the solution of the polyester resin in the liquid diluent. By the term "stably dispersed" it is meant that the particles are prevented from flocculating or aggregating due to a steric shell of polymer chains extending around the particles, which are solvated by the mentioned solution and therefore become elongated State. In this context the term "solvated" means that the polymer chains in question, if they were independent molecules, would in fact be soluble in the solution of the polyester resin. However, because the chains are in fact linked to the microparticles at some point along their length, the steric shell remains permanently attached to the particles. It should be noted that the stabilizing polymer chains to be used in a particular case will be selected taking into account the nature of the liquid diluent and the film-forming polyester resin concerned. In general this means that the chains have a degree of polarity similar to that of the diluent and the film-forming polyester, so that the combination of the latter is inherently a solvent for the polymer of which the chains are composed. Since in automotive paints, to which the present invention is primarily directed, the liquid diluent expediently has a relatively high degree of polarity (since it contains, for example, a considerable proportion of "strong" ester and ketone solvents),

809845/0797

it follows that the stabilizing chains on the microparticles are usually are of such a composition that they are inherently soluble in this type of liquid.

The manner in which the stabilizing chains are anchored to the microparticles is expedient in connection with methods for Manufacture of the particles discussed below.

The polymer microparticles can be made in a number of ways. Preferably, they are prepared by a method of dispersion polymerization of monomers in an organic liquid in which the resulting polymer is insoluble, in the presence of a steric stabilizer. Suitable processes for dispersion polymerization are generally known and are described in detail in the literature. As for the dispersion polymerization of ethylenically unsaturated monomers such as acrylic or methacrylic ^v ^ Vinylestern and styrene or derivatives thereof, the method consists fundamentally in the monomers in an inert liquid in which the monomers are soluble in which aber.das resulting polymer is insoluble to polymerize in the presence of an amphipathic stabilizer dissolved in the liquid or a polymeric precursor which can give rise to such a stabilizer by interpolymerization or grafting with a portion of the monomers in situ. For a general explanation of the above principles, reference should be made, for example, to GE-PS en 941 305, 1 052 241, 1 122 397 and 1 231-614 as well as to "Dispersion Polymerisation in Organic-Media" by KEJ Barrett (John Wiley and Sons , 1975). Suitable ethylenically unsaturated monomers are methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, vinyl acetate, vinyl propionate ", styrene and vinyl toluene. The special preparation of dispersions of crosslinked addition polymer particles can be achieved by adding the selected monomer pairs incorporated that (to-

809845/0797

ft 2818033

in addition to the polymerizable unsaturated groups) contain groups which enter into chemical reaction with one another such as the epoxy and carboxyl groups found in glycidyl methacrylate and methacrylic acid are present. When carrying out the processes which are particularly described in GB-PS 1 095 235 and 1 156 are described, for example, particles can be obtained in which such complementary groups are present which, although to this state have not yet reacted with one another, but can be induced to react with one another and thereby cross-links form by then heating the dispersion to a suitable elevated temperature. Crosslinked addition polymers can can also be produced in dispersion, indsm one in the Dispersion polymerization-subject monomers incorporates a minor proportion of a monomer that is related to the polymerization reaction is difunctional, such as ethylene glycol diethacrylate or diviny! benzene.

Of the unsaturated monomers mentioned above, methyl methacrylate is used a good choice when it is desired to have the polymer microparticles have a high Tg. If the microparticles are to have a low Tg, then ethyl acrylate or Vinyl acetate can be used, but a more convenient alternative may be methyl methacrylate in a smaller proportion "emollient" monomers such as butyl acrylate or butyl methacrylate, to copolymerize. The proportions used of such emollient However, monomers may need to be restricted otherwise there is a risk that the resulting interpolymer will be overly soluble, even in hydrocarbon diluents lower polarity than that of a stable dispersion of microparticles could be obtained. In the case of butyl acrylate as the softening honey monomer, for example, a proportion of 15% by weight should be based on the total monomers, must not be exceeded. Certain other emollient monomers, e.g. 2-ethoxyethyl acrylate or 2-Äthoxyäthylmethacrylat, can optionally in larger Proportions than the stated value are used, however, such monomers are not as readily available as the corresponding ones

809845/0797

lower allyl ester. Small amounts of comonomers, the carboxyl groups such as acrylic acid or methacrylic acid, can be incorporated (if the microparticles are to be crosslinked, then these proportions would be in excess of those used to crosslink by reaction with a co-reactive Honor, such as glycidyl methacrylate). Vice versa small (additional) proportions of epoxy monomer, e.g. Glycidyl methacrylate. Other functional monomers, such as hydroxyethyl acrylate or acrylamide can also are incorporated in smaller amounts into the monomers from which the microparticles are made.

The preparation of dispersions of condensation polymers is described, for example, in G3 patents 1,373,531, 1,403,794 and 1,419 described. Descriptions of processes for producing crosslinked polymer particles can also be found there. The ones that apply here are more general. Principles are the same as those related above with addition polymer dispersions, however, there is a difference in detail that is evident from the generally higher clear Nature of the monomers or starting materials from which the condensation polymers are derived results. That means namely, that the monomers in question are generally insoluble in the inert liquid in which the polymerization is to be carried out are. Accordingly, the first stage is dispersion polymerization the monomers in it, they in the inert liquid entvedsr as a liquid or as solid particles in one To bring a state of colloidal dispersion. In the second stage the polymerization of the monomers takes place in these particles instead of. There is an anphipathic stabilizing agent in everyone Step required, firstly, to stabilize the particles of the monomer, and secondly, to stabilize the particles of the polymer formed To stabilize, however, in appropriate cases a single stabilizing agent can be found that both these functions Fulfills. Instead of using a previously prepared amphipathic stabilizer, this method a suitable polymeric precursor can be used, the

309845/0797

by. Copolymerization or by grafting with a portion of the monomers can give rise to polynerisierenden to such a stabilizing agent in situ occasion. Reference is made here to GB-PA 19437/76.

Suitable monomeric starting materials for the preparation of microparticles from a condensation polymer are those for the production of such polymers by enamel or solution pol3 / m5risatior_stecliniken are known. For example, in the case of polyester microparticles, suitable materials are the polyvalent ones Alcohols and polycarboxylic acids previously / mentioned. In the case of polyamide microparticles, suitable monomeric starting materials are Amino acids such as 6-aminocaproic acid or 11-aminoundecylic acid, or the corresponding lactams ^ and / or polyamines, such as ethylenediamine, propylenediamine, hexamethylenediamine, Diethylenetriamine, triethylenetetramine or tris (aminomethyl) methane, in connection with the above-mentioned polycarboxylic acids. It should of course be pointed out that both in the case of polyester as well as in the case of polyamide microparticles, the mixture to be polymerized contain a proportion of a starting monomer which has a functionality greater than 2 if it is desired that the microparticles are crosslinked.

In all of the dispersion polymerization processes described above the amphipathic steric stabilizer is a substance whose molecule contains a polymeric component that is Liquid is solvated in which the dispersion is prepared, and contains another component that is produced by this Liquid is relatively poorly solvatable and which can associate with the polymer particles formed. Such a stabilizer is wholly soluble in the dispersion liquid, but the resulting solution will usually be both contain individual molecules as well as micfellar molecular aggregates in equilibrium with one another. The type of stabilizer, which is preferred for use according to the invention is a block or graft copolymer, which has two types of poly-

Γ " in connection with the film-forming polyester resin

'809845/0797

2B18093

kidney components contains: one consists, as stated above, of polymer chains that can be solvated by the dispersion liquid and the other component is made up of chains of polynes different polarity than the first type, which is accordingly caused by the liquid are not solvatable and which become anchored with the polymer microparticles. A particularly useful form of this Stabilizer is a graft copolymer that forms a polymer framework which contains the non-solvatable or 'anchoring component' and has a variety of solvatable polymer chains depending on the backbone. Suitable examples for such graft copolymers are those in which the backbone consists of an acrylic polymer chain which is predominantly derived from methyl methacrylate, and in which the pendant chains are residues of poly- (I2-hydroxystearic acid), which easily Solvatable by an aliphatic hydrocarbon mediura are. These copolymers can be prepared, for example, by first poly (12-hydroxystearic acid) with Glycidyl acrylate or glycidyl methacrylate converts, with the terminal -COOH group in the polymeric acid into an ester derivative is transferred that contains a polymerizable unsaturated group, and that this derivative is then mixed with methyl methacrylate and optionally together with minor amounts of other copolymerizable ones Monomers copolymerized., By using acrylic acid or methacrylic acid as subordinate comonomers it is possible to incorporate carboxyl groups into the backbone chain of the graft copolymer, which in this respect leads to useful results leads than the framework is thereby made more polar than it is the case when it consists only of methyl methacrylate units alone. This increased polarity has the consequence that the framework is depleted by a non-polar diluent, v / ie, for example, an aliphatic Hydrocarbon, after it becomes less solvatable, and as a result increases the force with which it interacts with the microparticle is anchored.

While it is preferred to remove the polymer microparticles by dispersion polymerization processes. as described above,

80984S / Q797

- te -

put, but it may be necessary to use the particles obtained in this way subject to further treatment to make them suitable for incorporation into the compositions used according to the invention close. This need can arise for the following reasons. The most suitable inert liquids in which the dispersion polymerizations carried out v / ground, are liquids of low polarity, such as aliphatic or aromatic hydrocarbons or mixtures thereof. The reason for this is that such liquids for the majority of polymers whether they are now addition or condensation polymers, represent nonsolvents and therefore the largest selection of polymer or mixed polymer compositions according to the properties which the desired Microparticles should have resulted. From the above discussion, however, it can be deduced that steric stabilizers, as they are suitable for the stabilization of microparticles in a simple liquid of low polarity, these no longer stabilize effectively when they are dissolved in the solution of the film-forming polyester resin (A) in the liquid diluent (B) to be brought. One relevant factor is that (B) is likely to be a relatively highly polar liquid is when it comes to the formulation of the automotive paints in question, and another factor that is probably more important is, is that the polyester molecules (A) with the chains of the stabilizing agent to the solvation effect of the Diluent competes. The consequence is that a transfer of the microx particles into the new environment destabilizes them and will result in flocculation.

According to the invention it is therefore preferred that the microparticles, which have been produced by a dispersion polymerization process, are further associated with a polymer, that is soluble in the volatile organic liquid component (B) of the base coating composition and also with the film-forming polyester resin (A) is compatible. This further polymer, hereinafter referred to as "auxiliary polymer", is

809845/0797

largely, not networked. It is assumed that when microparticles associated with an auxiliary polymer are introduced into the higher molecular environment of the solution of the film-forming polyester resin (A) in the organic liquid (B), the chains of the auxiliary polymer are now solvated and at least partly take over the function of the original ampliipathic stabilizer to keep the microparticles in a deflocculated, dispersed state. However, the scope of the present invention is in no way intended to be affected by this assumption. The microtool is most expediently associated with the auxiliary polymer in that the dispersion polymerization process is immediately followed by the polymerization of further monomer, from which the auxiliary polymer is to be derived, in the original inert liquid medium and in the presence of the original stabilizing agent.

In general, the auxiliary polymer must have such a composition have that it is compatible with the film-forming polyester resin (A). The monomer or monomers that make up the auxiliary polymer are to be produced, taking this requirement into account, is selected as it is for a person skilled in the art is obvious.

By introducing the microparticles so treated into the solution of the polyester resin (A) in the liquid (B), some of the auxiliary polymer can be dissolved away by this more polar medium, however it is believed that a considerable part of the auxiliary polym remains anchored to the microparticles (although they are now are solvated by the medium), for example due to the fact that they are while with the chains of the polymer microparticles their production devoured four den, or due to one. actual grafting onto the chains. If desired, can the stability of the treated microparticles in the more polar medium be improved by ensuring that covalent bonds between the chains of the auxiliary polymer and such of the microparticles are developed. This can, for example,

809845/0797

done by adding an unsaturated carboxylic acid to the monomers incorporated, from which the auxiliary polymer is made. The carboxyl groups so introduced are capable of reacting with epoxy groups that are present in the microparticles as a result of their use a slight excess of the latter groups for the purpose of crosslinking this polymer by reaction with carboxyl groups are present in the manner described above.

The incorporation of the microparticles produced by dispersion polymerization into the coating composition can be made by dispersing the microparticles (whether or not they have been treated with auxiliary policemen) mixed with a solution of the film-forming polyester resin (A) in a suitable diluent (B). Another possibility consists in separating the microparticles from the dispersion in which they were made, for example by centrifugation, Filtration or spray drying, and then the microparticles with the solution of a polyester resin (A) in a diluent (B) Mix as described above.

As an alternative to using dispersion polymerization processes The polymer microparticles can also, for example, by aqueous emulsion polymerization of suitable unsaturated ones Monomers are prepared using methods known per se in the art. The microparticles are then obtained in the form of a charge stabilized dispersion from which the particles themselves may have been separated, for example by spray drying. The microparticles are then back in solution for incorporation into the coating composition the film-forming polyester resin dispersed in the diluent, preferably by methods which impart high shear to the mixture, e.g. in a pin mill or in a three-roll mill, in a manner analogous to what happens when a pigment is dispersed. According to another analogy to a pigment dispersion can have the required steric stability of the microparticles then simply as a result of the inherent tendency ''

809845/0797

of the film-forming polyester (which by definition is due to the diluent solvated) to associate with the particles can be achieved, for example through the interaction of polar groups in the polyester resin or in the microparticles are present. In the production of microparticles by Aqueous emulsion polymerization can have a smaller proportion of difunctional unsaturated compounds are incorporated into the polymerizing monomers to give rise to a crosslinked polymer to give that in the solution of the film-forming polyester resin (A) in. Diluent (B) is insoluble, whatever the nature of the latter always has. Here again, as in the case of microparticles, which are prepared by dispersion polymerization, desirably, emulsion polymerization with to continue a second charge of non-difunctional monomers (i.e. crosslinking) material and which gives rise to a polymer that reacts with the solution of the polyester resin (A) is compatible in the diluent (B), i.e. in other words that an auxiliary polymer is associated with the microparticles, which has the same function as described above.

As already stated, the polymer microparticles (C) are present in the compositions used according to the invention in a mer-gG of less than 3% of the total weight of film-forming polymer (A) and microparticles.

For purposes of definition, the term "polymer microparticles" is to be understood as referring to the actual microparticles in the case where an auxiliary polymer is used and also to that part of the auxiliary polymer which is associated with the microparticles and which is not covered by the Diluent (B) can be removed under the conditions of the insolubility test described above. When the compositions are used for use in the manufacture of top coatings (as opposed to their use as undercoats mentioned above), then the amount of polymer microparticles incorporated is preferably 3 to 30% of the total weight of film-forming polymer and microparticles.

809845/0797

The compositions blended in the process according to the invention can, in addition to the polyester resin (A), the diluent (B) and the polymer microparticles (C), also contain pigments which are customary in coating technology. Such pigments can have a particle size in the range from 1 to 50 uc and an inorganic nature, for example titanium dioxide, iron oxide, chromium oxide, lead chromate or carbon black, or an organic nature, such as plithalocyanine blue, phthalocyanine green, carbazole violet, anthrapyrinidine yellow, plavanthrone yellow, isoindoline blue, indoline blue, Quinacridene violet and perylene red. Of particular interest in this context are metal pigments, which consist of flat flakes of aluminum, copper, tin, winding or stainless steel, because they can be used to achieve so-called "metal effects", by means of which different light reflection depending on the viewing angle is achieved. All of the above pigments can be present in the coating compositions in amounts of from 2 to 50fo of the total weight of all of the film-forming material present. The term "pigment" also includes conventional fillers and extenders such as talc and kaolin.

Such pigments, whether they have a metallic or other skin, can be incorporated into the compositions with the aid of known dispersants such as an acrylic polymer which is mixed with the polyester resin (A) are compatible, incorporated v / ground.

Optionally, the compositions may additionally contain other known ones Contain additives such as viscosity modifiers, e.g. benton or cellulose acetate butyrate.

As already indicated, curing agents can furthermore be incorporated in order to bring about the curing of the polyester resin (A) or to support. Suitable types of crosslinking agents are diisocyanates, Diepoxides and especially aminoplast resins, i.e. condensates of formaldehyde with nitrogenous compounds, such as urea, melamine, thiourea and benzoguanamine, or

809845/0797

the lower alkyl ethers of such condensates in which the alkyl groups Have 1 to 4 carbon atoms. MeIanir./Fornialaehyd- condensates are particularly suitable, v / orin a considerable proportion of the methylol groups is etherified by reaction with butanol. The relationship from crosslinking agent to crosslinked acrylic or other polymer in the composition can vary widely, however are im general weight ratios of 50:50 to 90:10 of polymer too satisfactory crosslinking agent. However, the exact ratio to be used depends on the properties desired of the finished film, but a preferred range of the weight ratio of polymer to crosslinking agent is the one good balance of properties gives between 60:40 and 85:15.

The substitution can also use a suitable catalyst for the crosslinking reaction, such as an acid-reacting one Compound, e.g. acid butyl maleate, acid butyl phosphate or p-toluenesulfonic acid. Alternatively, the desired catalytic effect can be caused by carboxyl groups present in the film-forming polyester resin (A).

Following the spray application of the coating composition onto the substrate surface and evaporation of the volatile liquid diluent to produce a polymer film on the surface, the polyester resin component (A) can then be allowed to cure by atmospheric oxidation or to react with a crosslinking agent present, as appropriate. Optionally, the curing process can be assisted by heating the coating, for example to a temperature up to 160 ⁰ C.

Any spraying method can be used to apply the composition, such as compressed air spraying, electrostatic spraying, hot air spraying, and airless spraying, both manual and automatic methods being suitable . Under these application conditions, coating with an excellent

8098AS / 0797

BATH ORIGINAL

Gloss obtained compared to the coatings known after Processes are obtained in that they have advantages in that excessive flow does not occur when applied especially at sharp edges and corners of a substrate with complicated Shape. Scratches in the surface to be coated are also better covered. Films up to a dry thickness 0.1 mm can be applied without snot noses or the metallic effect being impaired.

Alternatively, the method according to the invention can be used in a double coating The process can be modified, commonly called the "undercoat / clearcoat" process is referred to and in the production of metallic effect coatings, of which further discussed above is of particular value. First of all, the surface of the substrate is covered with the uterine coating applied, which contains the Metallpignent and is formulated so that a maximum metallic effect is achieved, whereupon over an unpigmented top coat is applied to the base coat which gives high gloss without modifying the characteristics of the undercoat. The one defined above Process according to the invention in which a metal pigment is used is of a special fourth for making the undercoat in this type of application process.

Accordingly, the invention also relates to a method of production a multilayer coating on the surface of a substrate, which is characterized in that one

(1) a base coating composition by spraying onto a substrate applies, which includes:

(A) a film-forming polyester resin as defined above;

(B) a volatile organic liquid diluent in which the polyester resin (A) is dissolved;

809845/0797

(C) Polymer microparticles as defined above, which are in the solution of the film-forming polymer

are insoluble in and stably dispersed in the liquid diluent, in an amount of at least 1O? o of the total weight of the film-forming Polymer (A) and the microparticles;

(D) Pig: nentpartchen, which are also in the solution of the film-forming polyester resin dispersed in the liquid diluent;

(2) a polymer film made from that applied in step (1) Prepares coating composition on the substrate surface;

(3) Apply a transparent coating to the base coat obtained in this way Applies a topcoat composition containing:

(E) a film-forming polymer;

(P) a volatile carrier liquid for the polymer

and

(4) a second polymer film on the base coat film the composition applied in step (3).

The polyester resins (A), the diluents (B) and the polymer microparticles (C) which are suitable for use in the above process are the same as described above. The pigment particles (D) can be any of those already described above, but the method is of particular value in FIG Use of metal pigments, as already indicated.,

009845/0? $?

- 2q -

It should be noted that a high maximum level of microparticles can be used in this process, in contrast to the previously described process. This requirement takes into account the fact that a basic coating etch, especially one which contains a metal pigment, requires a much higher degree of control of the flow of the material during application than is the case with a composition which is intended for the production of a top layer coating. The ϊ-Ienge to Hikroteilchen 10 used is preferably up to 3O? 6 of the total weight of filmbildeiidem polymer (A) and & en microparticles.

Optionally, the basecoat composition can additionally contain other known additives, such as viscosity modifiers, for example bentone or cellulose acetate butyrate.

The polymer component (E) of the topcoat composition used in step (3) of the process of the invention can generally be any suitable film-forming polymer. Thus it can be a film-forming polyester resin of one of the types described above, in which case the topcoat composition can additionally contain a crosslinking agent. Alternatively, the polymer (E) can be one of the known acrylic film-forming polymers which are predominantly derived from esters of acrylic or methacrylic acid. Such polymers can be of the thermoplastic type, in which case step (4) of making the second polymer film only requires the evaporation of the volatile carrier liquid. Alternatively, they may be of the thermosetting type, which may require the assistance of a crosslinking agent of a similar type as already described in connection with the polyester resins, and also the application of heat in "step (4). Unlike the polyester resins in In the basecoat composition, the polymer (E) in the topcoat composition can be either a solution or a stable dispersion in the volatile carrier liquid (F) of the composition.

809845/0797 ^BÄD ° R'CWL

2818083

Thus, the carrier liquid (F) can either be a solvent or a sealant for the top coat poljiner. If the Liquid is a solvent, it can be any volatile organic liquid or liquid mixture, as mentioned above as being suitable for use in a composition containing the polyester resin. ¥ enn die If liquid is supposed to be a nonsolvent, then it becomes an essential one have lower polarity than those previously mentioned. It can consist of one or more aliphatic hydrocarbons exist, such as hexane, heptane or petroleum fractions with low aromatic content, possibly mixed with liquids of high polarity, as already mentioned above, provided that the overall blend is a nonsolvent for the topcoat polymer.

If the topcoat composition is a polymer dispersion then it will generally be sterically stabilized Acting dispersion, the polyra particles are stabilized with the aid of a block or graft copolymer, one of which polymer component insolvatable by this liquid and is associated with the disperse polymer. The well-known principles by which such dispersions are made have been discussed above in connection with the preparation of microparticles for the basecoat composition described.

The topcoat composition can in some cases both Contains polymer in solution as well as polymer in dispersion. The soluble polymer can be a previously prepared polymer of others I-ionomer composition as the dispersed polymer, which, unlike the latter, is soluble in the carrier liquid (F) and added as a solution in the same to the dispersion will. However, it can alternatively also occur during the preparation of the disperse polymer as a result of a preferred polymerization certain monomers present are formed. It can also be a polymer that was originally produced in dispersion.

80984S / 0797

which, however, unlike the main film-forming agent, goes into solution when other than the continuous liquid phase of the dispersion Liquids with stronger dissolving power than the latter in formulating a paint with the required application properties be admitted.

Usually, the top coat composition becomes permanent be colorless so that the pigmentation effect of the primer composition is not substantially modified, but in certain instances it may be desirable to modify the topcoat composition to give a transparent staining.

The first stage of the process is the basecoat composition applied to the surface of the substrate that has previously been primed or otherwise treated in the usual manner can be. The substrates which are of particular interest according to the invention are metals such as steel or aluminum, which are commonly used for the manufacture of automobile bodies. However, other materials, such as e.g. Glass, ceramics, wood, and even plastics, can be used provided they can withstand the temperatures at which the finished multilayer coating is cured. After the basecoat composition is applied, the Surface of the substrate formed a polymer film. Optionally, this can be achieved by the fact that the substrate and the applied coating is heated to volatilize the organic liquid diluent. It's within range the invention to use a heating temperature sufficient to crosslink the base coat film in such cases where curing of the polyester resin requires such a process. However, there is a significant advantage to the present Method in that it is sufficient to carry out only brief drying at or near room temperatures, i.e. without that the polyester resin is cured to ensure that the top coat composition adheres to the base coat film can be applied without any tendency that

809845/0797

the former mixes with the latter or dissolves the latter, and in such a way that the correct orientation of the metal pigment is disturbed, so that an optimal metal effect is obtained will. Typically, a drying time of 1 to 5 minutes at a temperature of 15 to 30 ° C ensures that mixing of the both coatings is prevented. At the same time the base coat film sufficiently by the topcoat composition wetted so that a satisfactory adhesion between the coatings is obtained.

After the top coat composition is applied to the base coat film, the coated substrate undergoes a curing operation subjected, in which the base coat and optionally also the top coat by autoxidation and / or Crosslinking is cured with the aid of crosslinking agents which may be present. This hardening operation is increased at an Temperature performed as it is with the thermally cured coating composition is common, e.g. at a temperature in the range from 100 to 140 ° C, but possibly also at a lower temperature, provided that the crosslinking system is sufficiently reactive.

The basecoat composition can be applied to the substrate applied by one of the spraying techniques described above. The top coat composition can then by any convenient method such as brushing, squirting, dipping, or flowing, it is applied but preferably also applied by spraying, since then the best results in terms of the gloss of the entire coating can be achieved. The use of the basecoat composition containing both polyester resin and polymer microparticles, gives a significantly improved control over the orientation of the metal pigment under the conditions of spraying, so that an improved metallic effect is achieved.

809846/0797

- 25? -

The invention is illustrated by the following examples, wherein all parts and percentages are expressed by weight.

example 1

(A) Alkyd resin coating composition containing polymer microparticles

(1) Manufacture of Polycem ik redeilche n

In a container equipped with a stirrer, a thermometer and a reflux condenser, the following was placed:

Aliphatic hydrocarbon (boiling range 20.016 parts 140 to 156 ° C; no aromatic content)

Methyl methacrylate 1,776 "

Methacrylic acid 0.056 "

Azodiisobutyronitrile. O, 14O "

Graft copolymer stabilizer (33% solution, 0.662 " as described below)

The vessel and contents were purged with inert gas, and the temperature was raised to 100 ⁰ C and 1 st kept at this value to prepare a disperse "seed polymer". The following ingredients were premixed and introduced into the container at a steady rate over a period of 6 hours, with stirring and heating maintained at 100 ^° C:

Methyl methacrylate Glycidyl methacrylate metha eryic acid Azodiisobutyronitrile dimethylamino ethano1

Graft copolymer stabilizer solution (as below

described

809845/0797

52.459 Parts 0.331 it 0.331 Il 0.203 η 0.070 II 6,810 It

-3Q-

aliphatic hydrocarbon (boiling range. 140 33.166 parts

Ms 156 ⁰ C)

100,000 parts

The contents of the container were ^{kept at 100 °} C. for a further 5 hours, with complete conversion of the monomers into a fine dispersion, the insoluble gel-like polymer microparticles (21 to 22% of the total dispersion) combined with uncrosslinked polymer particles (23% o of the entire dispersion).

The graft copolymer stabilizer used in the above process was obtained as follows. 12-hydroxystearic acid was added up to an acid value of approximately 31 to 34 mg KOH / g (corresponding to a molecular weight of 1650 to 1800) self-condensation and then with an equivalent Ilenge of glycidyl methacrylate implemented. The resulting unsaturated ester was in a weight ratio of 2: 1 with a mixture of methyl ethyl acrylate and acrylic acid in a ratio of 95: 5.

(2) Modification of microparticles ax auxiliary polymer

In a container equipped as described in step (1) above, 63.353 parts of the dispersion obtained in step (1) above were placed. This dispersion was ^{heated to 115 °} C. and the container was flushed with inert gas. The following ingredients were premixed and at a steady rate over a period of 3 st to the stirred contents of the container were added while the temperature was maintained at 115 ° C.

Methyl methacrylate hydroxyethyl acrylate methacrylic acid Butyl acrylate 2-ethylhexyl acrylate Styrene

809845/0797

3,342 Parts 1.906 It 0.496 11 3,691 It 3.812 11 R 7ΊΟ It

Azodiisobutyronitrile 0.906 parts

priis-Octy! mercaptan 0.847 "

Graft mixing polymer stabilizer solution (as in step

(1) described) 1.495 "

After the addition had ended, the contents of the container were kept at 115 ° C. for a further period in order to achieve full conversion of the monomers. Finally, 13.940 parts of butyl acetate were added to bring the total batch to 100,000 parts. The dispersion thus obtained had a total film-forming solids content of 45 to 6%. The content of the insoluble gel-like polymer microparticles was 27.0 to 27.5%.

(3) Making a hollow base

The following ingredients were ground in a ball mill:

Titanium dioxide pigment 7.8 parts

Medium chrome pigment 27.8 "

Scarlet chrome pigment. 18.1 "

Dispersing resin (49? O solids containing solution- 29.6 " solution in xylene)

Xylene. 16.7 "

(4) Preparation of a coating composition The following ingredients were mixed:

Grinding base (as described above under (3)) 150.34 parts of melanin / formaldehyde resin (62 ^ solids contained 63.52 " solution in butanol)

Alkyd resin solution (as described below) 133.43 " Polymer microparticle dispersion (as above under- 35.46 ■ "

(2) described)

Dipentene 24.00 '"

809845/0797

Butyl acetate 8.00 parts

Xylene 51.00 "

The alkyd resin solution used in the above formulation was a 63% solids solution in xylene of a resin containing 34% oil longitudinally produced by the condensation of coconut oil, trimethylolpropane, Glycerin, benzoic acid and phthalic anhydride in the molar ratios 0.806: 3.273: 0.192: 0.531: 3.906

(B) Alkyd resin coating composition: which does not contain polymer microparticles

The following ingredients were mixed:

Grinder base as described in (A) (3) above 150.34 parts

Melamine / formaldehyde resin (contains 62% solids - »63.52" de solution in butanol)

Alky resin solution (as described above under (A) (4)) 157.58 "

Dipentene 24.00 "

Butyl acetate 8.00 "

Xylene 51.00 "

(C) Application of coating compositions

The compositions prepared under (A) and (B) above were applied by spraying onto vertical primed steel plates punched 25.4 mm apart with holes 6.3 mm in diameter. The spraying was done in such a way that the film thickness gradually increased from the top to the bottom of the plate. The applied coatings were allowed to evaporate for 45 minutes and then baked ^{at 130 ° C. for 10 minutes.}

The film thickness at which the coatings began to snot at the edges of the holes was then determined. For the composition (A) containing polymer microparticles,

809846/0797

the thinnest film thickness was 0.1 mm. In the case of the composition (B), that did not contain microparticles was the thinnest film thickness 0.06 mm.

Example 2

Grundbe ichtungs sch / Klarbsβchichtu ngs method using a primary coating together be part mensetzun g having a content of _ PoIymerKiikro che n

(A) Preparation of coating Grundbe szu s a mmensetzung The following ingredients were mixed:

Melamine / formaldehyde resin (67 & Lge solution in butanol) 3-3.00 parts

Porymer microparticle dispersion (as in Example 1 83.56 "

Part (A) (2) described)

Alkyd resin solution (as described below) 26.64 "

Dispersion of carbazole violet (6.1% in xylene) 10.12 "

Dispersion of phthalocyanine blue (9.7 / -ά in xylene). 20.23 «

Dispersion of carbon black (14.2S6 in xylene) 2.52 "

Dispersion of aluminum flakes (35% paste in 81.04 "

Xylene)

2-ethoxyethyl acetate 50.64 "

Butyl acetate 35.00 "

The alkyd resin solution used in the above formulation is a 70% solution of a resin in xylene, the resin being produced by condensation of coconut oil, trimethylolpropane, glycerol and phthalic anhydride in the molar ratios 1.0: 4.05: 0.5: 5.14 had been made.

(B) Disclosure Process

100 parts of the basecoat composition, which had been prepared as under (A), was made by adding 87 parts of butylace-

809845/0797

was diluted so that a viscosity of 23.25 seconds in a BS-B3-3 cup at 25 ⁰ C was obtained. The diluted paint was spray applied to a primed metal plate so that a film thickness of 0.02 mm was obtained after all of the solvent had evaporated. After einer.2 min permanent Äbdaspfperiode at room temperature, the plates were coated with two coats of a thermosetting acrylic clear composition, zx \ ^f i can see the coatings an evaporation time of 2 minutes was allowed. The dry film thickness of the clear coating was 0.06 mm. After a final evaporation time of 10 minutes at room temperature, the plates with the coatings were baked at 127 ° C. for 30 minutes.

The coatings obtained in this way had an excellent appearance with a uniform aluminum metal effect, with no trace of movement of the metal flakes being discernible. There was no sinking of the clear top coat into the base coat, so that the very high gloss level produced by the clear coat was in no way impaired by the base coat, although there was still excellent adhesion between the coverings in the fired panels . The coating also had good flexibility and moisture resistance.

The clear one used in the top coat of the above process Acrylic composition was made as follows:

Butylated melamine / formaldehyde resin (60% solution 22.0 parts in butanol)

Dipentene 9.5 ^AD

Butyl glycolate 4.5 "

Butanol 2.5 "

2; & ge solution of a silicone oil 0.4 "

non-aqueous dispersion of a thermosetting 50.0 " Acrylic resin in aliphatic / aromatic hydrocarbon mixture (42 ^ solids)

8098A5 / 0797

2818033

Solution of a thermally hardening acrylic resin in 19.5 parts Xylene / butanol (5OJO solids)

The composition had a viscosity of 60 seconds, measured at 25 ^° C. in a B3 beaker in accordance with BS 1733: 1955.

Example 3

The procedure described in Example 2 was repeated except that the 26.64 parts of the alkyd resin solution described there through 31.07 parts of a 60% solution of an alkyd resin ■ in xylene replaced The alkyd resin is obtained by condensation of azelaic acid, phthalic anhydride, trimethylolpropane and neopentyl glycol in the molar ratios 0.346: 0.654: 0.369: 0.777.

Example 4

Alkyd resin coating compositions containing polymer microparticles in various proportions by weight

Three compositions, designated I, II and III, were prepared by having the following ingredients in the specified Proportions were mixed:

I II III

Melamine / formaldehyde resin (62? A solid 60.0 72.5 60.0 substance-containing solution in butanol) 119.2 119.2 119.2 white grinding base containing TiO ₂ 143.1 107.9 128.2 Alkyd resin solution (as in example 2 described) 1.2 1.2 1.2 Silicone oil solution (2%) 8.0 8.0 8.0 Isobutyl alcohol 20.0 ■ 20.0 20.0 Dipents 56.0 50.0 83.0 Xylene

809845/0797

28Ί8093

Polymeric microparticle dispersion (as in at-32.9 65.8 game 1, part (A) (2) described)

thermosetting acrylic polymer (65 ° <> ige - - 22.9 Solution

Best solids content, % 51.14 50.59 50.03

Microparticle content, '5i non-volatile constituents 5 10 -. 0 components (based on non-volatile EarzkoEiponentsn)

The primed I-tall panels were sprayed with each of the three compositions to produce a "wedge coat" of gradually varying film thickness. Each plate was 45 min and then allowed to stand vartikal - again in a vertical position - baked 10 min at 130 ⁰ C. The film thickness at which snot formation first occurred was then determined in each case. The panel coated with Composition III resulted in snotty nose formation at a film thickness of 60 to 65 µm and above, but the panels coated with Composition I and II only produced snot nose formation at a film thickness of 75 µm and above.

Example 5

A polyoster coating composition containing polymer microparticles using an alternative crosslinking agent

The following ingredients were ground in a ball mill:

Polyester containing hydroxyl groups (hydroxyl 17.11 parts content 8, V / o, 90% solution in 2-butoxyethyl acetate)

Polymer microparticle dispersion (as in Example 1, 8.39 " Part (A) (2) described)

Butyl acetate 6.20 "

Titanium dioxide, 34.30 "

809S45 / 0797

- 3V -

After peeling and discharging from the ball mill, the following became Components added:

Zinc octoate (containing 22% Zn), 0.80 parts silicone oil solution (2%) 2.00 "

2-ethoxyethyl acetate 3.10 "

Butyl acetate 2.30- »

15.15 parts of an aliphatic polyisocyanate (100% non-volatile content, NCO content 23.5%) were added to the above charge. After mixing, the resulting composition was sprayed onto a primed plate in the manner described in Example 4, allowed to evaporate for 30 minutes and then baked ^{at 80 ° C. for 30 minutes.}

A similar composition was made, but with the Polyaerial proteins have been omitted. For spray application like found in Babeispiel 4 vrarde that they have a significantly lower Exhibited snot resistance than the above composition containing the microparticles.

Example 6

Polyester coating composition comprising metallic effect with and without polymer microparticles

The following set of components, which are listed in columns I and II have been mixed:

I II

butylated helamine / formaldehyde resin 39.3 parts 39.3 parts (67? £ solid containing solution in

Butanol)

Dispersion of phthalocyanine blue (9.75 & 3.63 "3.63" in xylene)

809845/0797

59.83 Il 117.6 η 20.1 Il 20.1 η 20.1 H 20.1 η 0.9 Il 0.9 π 30.0 tr 30.0 π 77.31 η - 18.15 Il 18.14 Il _ 20.0 π

Dispersion of phthalocyanine green blue 2.34 parts 2.34 parts (3.655c in xylene)

Alkyd resin solution (as described below) 59.83 butyl acetate
Methyl ethyl ketone

flowing polymer (10 & Lge solution in xylene)
Diper.ten

modified microparticle dispersion
(as described in Example 1 (A) (2)) Dispersion of aluminum flakes (20 & - .18.15 ige paste in xylene)
Xylene

The alkyd resin used in the above formulation was a 70-4 type Solution of a resin with 34? 6 oil length in a mixture of xylene and Isobutanol in a weight ratio of 4: 1, this resin being produced by condensation of coconut oil, trimethylolpropane, glycerine and phthalic anhydride was obtained in the molar ratios 1.0: 4.05: 0.5: 5.14.

The two compositions I and II had a viscosity of 33 seconds, measured in a B.S. B3 beaker at 25 ° C

Four coats of each composition were applied wet-on-wet to primed metal panels, leaving a 1 minute flash between coats. After a final 10 min continuous evaporation time, the panels were baked for 30 minutes at 127 ⁰ C.

The control over the aluminum flake pigment during application was significantly better in the case of composition I than in the case of composition II, since no "shear" effects and no "blackedging" were observed in the coatings obtained.

& 09845/0797

Claims (17)

Claims 1./Verfahren, for the production of a surface coating, thereby characterized in that a coating composition is applied to a substrate by spraying, which includes: (A) a film-forming polyester resin as defined below; (B) a volatile organic liquid diluent, in which the polyester resin (A) is dissolved; (C) Polymer microparticles as defined below in an amount of at least 3% of the total weight of the resin (A) and the microparticles which are insoluble in the solution of the polyester resin in the diluent (B) and are stably dispersed therein, and that the volatile diluent (B) is then evaporated off and forms a polymer film on the substrate surface. 2. The method according to claim 1, characterized in that that the polymer microparticles are derived from one or more ethylenically unsaturated monomers. 3. The method according to claim 2, characterized in that that the polymer is a polymer or copolymer of one or more alkyl esters of acrylic acid or methacrylic acid. 4. The method according to claim 1, characterized in that that the polymer microparticles consist of a condensation polymer. 5. The method according to any one of claims 1 to 4, characterized in that the polymer microparticles by a method of dispersion polymerization of monomers in S09845 / 0797 an organic liquid in which the resulting polymer is insoluble in the presence of a steric. Stabilizer for the particles have been made. 6. The method according to claim 5, characterized in that the steric stabilizer used in the preparation of the Polymeraikropeilchen is a block or graft copolymer whose I-iolekül contains a component that is made by the organic? Liquid-solvatable polymer chains, and contains a further component, which consists of polymer chains of different polarity which cannot be solvated by the organic liquid and which are anchored with the polymer microparticles. 7. The method according to claim 6, characterized in that that the steric stabilizer is a graft copolymer is that one which cannot be solvated by the organic liquid Has polymer backbone and a variety of polymer chains that depend on the backbone and through the organic liquid are solvatable. 8. The method according to any one of claims 5 to 7, characterized in that the microparticles continue with one. Polymer (hereinafter referred to as auxiliary polymer) have been associated, which is soluble in the volatile organic liquid (B) of the composition and also with the fUmbildenden ^ arz (A) is compatible. 9. The method according to claim 8, characterized in that that the microparticles have been associated with the auxiliary polymer that the dispersion polymerization, through which the microparticles are obtained, immediately a polymerization of another monomer, from which to derive the auxiliary polymer in the original inert liquid medium and in the presence of the original stabilizer. 809845/0797 10. The method according to any one of claims 1 to 4, characterized in that the polymer microparticles by eir.c aqueous emulsion polymerization of unsaturated monomer have been prepared. 11-. Method according to claim 10, characterized in that that the polymer microparticles are further processed with an auxiliary polynesr have been associated. 12. Verfahr or: according to one of claims 1 to 11, characterized in that the polymer microparticles (C) in a K-length from 3 to 3055 of the total weight of the film-forming Polymer (A) and microparticles (C) are present. 13. The method according to any one of claims 1 to 12, characterized in that the applied to the substrate Composition additionally contains a pigment. 14. The method according to claim 13, characterized in that that the pigment is a metal flake pigment. 15. A method for producing a multilayer coating on cer surface of a substrate, characterized in that one (1) a base coating composition by spraying onto a substrate applies, which includes: (A) a film-forming polyester resin as defined below; (3) a volatile organic liquid diluent in which the polyester resin (A) is dissolved; (C) polymer microparticles as defined below, are insoluble in the solution of the film-forming polymer in the liquid diluent 809845/0797 BATH ORIGINAL iond are stably dispersed therein in an amount of at least 10% of the total weight of the film-forming polymer (A) and the I-drooping particles; (D) pigment particles, which are also in the solution of the filnoildenaen polyester resin in the liquid diluent are dispersed; (2) a Folymerxilm from that applied in step (1) Coating composition on the substrate surface manufactures; (3) on the base coat obtained in this way, apply a transparent ■ te topcoat composition applies the following contains: (E) a film-forming polymer; (F) a volatile carrier liquid for the polymer (E); and (4) a second polymer film on the base coat film from the composition applied in step (3). 16. The method according to claim 15, characterized in that that the polymer microparticles (C) in an amount of 10 to 45/0 of the total weight of the film-forming polymer (A) and the microparticles (C) are present. 17. The method according to claim 15 or 16, characterized in that the step (2) is carried out. that the basecoat composition is allowed to dry on the substrate for 1 to 5 minutes at a temperature of 15 to 30 ^{° C.} 809845/0797